Small boat carrier

ABSTRACT

The invention is a small boat carrier or straddle-type trailer for boat yard use. The carrier is characterized by a single unitary open-ended horizontal U-frame which rides upon a pair of independent opposing multiple wheeled truck units disposed beneath the port and starboard after ends of the U-frame. The forward or closed end of the U-frame rides upon a free-wheeling swivel-mounted dolly unit which can be coupled to a tow truck or small tractor. The U-frame can be raised or lowered by one or more hydraulic rams which comprise extensible frame supporting means interposed between the truck units and the superjacent Uframe. Being devoid of load-bearing cross-members, the U-frame alone constitutes the sole structure which supports the hull of the boat to be moved. To operate, the carrier is backed into position beneath a boat and straddling the fixed support upon which the boat rests. The U-frame is hydraulically elevated to lift the boat clear of the fixed support, and the entire assembly is then ready for towing to another location.

United States Patent Weaver et al.

May 16, 1972 [54] SMALL BOAT CARRIER [22] Filed: June 18, I970 [21]Appl.No.: 47,183

Primary Examiner-Benjamin Hersh Assistant Examiner-Robert R. SongAuomey-Sidney W. Russell [57] ABSTRACT The invention is a small boatcarrier or straddle-type trailer for boat yard use. The carrier ischaracterized by a single unitary open-ended horizontal U-frame whichrides upon a pair of independent opposing multiple wheeled truck unitsdisposed beneath the port and starboard after ends of the U-frame. Theforward or closed end of the U-frame rides upon a free-wheelingswivel-mounted dolly unit which can be coupled to a tow truck or smalltractor. The U-frame can be raised or lowered by one or more hydraulicrams which comprise extensible frame supporting means interposed betweenthe truck units and the superjacent U-frame. Being devoid ofload-bearing cross-members, the U-frame alone constitutes the solestructure which supports the hull of the boat to be moved. To operate,the carrier is backed into position beneath a boat and straddling thefixed support upon which the boat rests. The U- frame is hydraulicallyelevated to lift the boat clear of the fixed support, and the entireassembly is then ready for towing to another location.

7 Claims, 8 Drawing Figures PATENTEDHY 16 I972 3. 663 O40 sum 1 OF 4FIG.1

NVEN QRS CHESTER 1 wax. a 1 CHARLES L. HOFFBERGEP,II

PATENIEBIAY 16 1972 SHEEI 3 BF 4 FIG.4

FIG.5

SMALL BOAT CARRIER BACKGROUND OF THE INVENTION AND PRIOR ART The presentinvention relates broadly to the art of opposed shelf-type elevatortransporters. The invention is more par ticularly addressed to aself-loading straddle-type carrier or trailer especially designed tomove small boats from one place to another within and about a commercialboat yard.

The past decade has witnessed impressive growth in the pleasure craftand yachting industries. There has naturally been a markedly increaseddemand by the boating public for the services of boat yards and relatedfacilities. The limited availability of suitable waterfront sites,however, prevented a responsive increase in the number of new yards aswell as in the size of existing yards. Consequently, storage space is ata premium and present day yards are, almost without exception, extremelycrowded. In addition, the services provided by many boat yards includenot only the traditional functions of storage and repair, but also thesale and display of new and used boats. These activities require thatboats be constantly shuttled about from one place to another in a boatyard, i.e., from a typically high density storage area to a show room orto used or new boat display lots. A very common occasion is that ofmoving a one or two ton boat a relatively short distance; three or fourmen are usually required for the job, together with a mobile crane and aheavy trailer. The process is not only time-consuming but expensive inview of high labor costs and the utilization of sophisticated movingequipment for even relatively light loads. There is, therefore, animmediate need for improved and simplified boat transportation apparatusdesigned for the special task of moving small boats short distances inand out of crowded situations in a boat yard.

The prior art has recognized this need to a limited extent. At least onespecially designed boat carrier has been suggested to meet the problem.Such apparatus employs pneumatically powered rotatable longitudinalbeams astraddle the hull which in tu rn support and elevate a pluralityof longitudinally spaced disconnectable transverse load bearingcrossbars. All of the crossbars must be manually removed before the maintrailer portion can be backed into position beneath the boat in order toclear the fixed boat supporting means. The crossbars are then manuallyreinserted so as to be athwart and beneath the keel of the boat. Onlythen can the assembly be elevated to lift the boat free of its fixedsupport. Since the boat when raised rides upon its keel, it isinherently unstable and auxiliary supports are required to stabilize theload. Such a procedure obviously entails a good deal of work and doesnot significantly reduce labor costs. Another drawback to this prior artapparatus is that it cannot easily accomodate boats the fixed support ofwhich is a more or less continuous cradle type of support, such as oneconstructed of stacked railroad crossties. In the latter instance it isoften necessary to partially disassemble the cradle before theload-bearing crossbars can be inserted to support the hull, thus furtherincreasing the labor involved. Another prior art apparatus which atfirst blush might appear adaptable for moving small boats comprises twonested U frames, the outer frame being a non-elevatable wheeled carriageor chassis member, and the inner frame being the elevatable load-bearingmember. Such a design, however, is unduly cumbersome and heavy. Itrequires at least two men to operate. And it is of necessity wider thanthe beam of the largest boat for which it is designed, hence is notsuitable for crowded areas.

OBJECTS OF THE INVENTION It is a principal object of our invention toprovide a boat carrier which is light and durable and requires nospecial skills to operate.

It is another object of our invention to furnish a boat carrier which isparticularly designed to move small boats in and out of crowded areas ina boat yard.

It is a further object of our invention to provide a boat carrier whichcan be operated by a single workman.

It is still another object of our invention to disclose a boat carrierwhich is no wider than the beam of the boat to be moved.

It is a more particular object of our invention to describe a boatcarrier having a maximum load capacity of approximately 4,500 to 5,000lbs. and accomodating a maximum boat length of up to about 24 feet.

Still another object of our invention is to disclose a boat carrierwhich is extremely maneuverable so that the entire carrier with boatupon it can be moved into or out of a space exactly the width of theboat or exactly the width of the carrier.

A still further object of our invention is to provide a straddle-typeboat carrier in which the sole boat supporting structure is a horizontalU-frame, the legs of the U contacting the hull on either side of thekeel and parallel therewith to furnish a stable support.

Another more specific object of our invention is to provide a boatcarrier in which the after mobile supports comprise multiple wheeledtandem-type trucks which are pivotally connected to the U-frame, thusaffording a smooth ride over rough terrain and eliminating the need forsprings.

These and other objectives and advantages of our invention will beapparent to those skilled in the art in light of the detaileddescription of the invention to follow.

SUMMARY OF THE INVENTION A broad embodiment of our invention relates toa boat carrier comprising a substantially horizontal U-frame defined bya pair of laterally spaced apart substantially parallel port andstarboard longitudinal beams and a transverse beam connecting theforward ends of the longitudinal beams. The after end of the U-frame isopen and the area bounded by the U-frame is unobstructed from its afterend throughout substantially its entire length. A first wheeled truckunit is positioned beneath the port beam. A second wheeled truck unit ispositioned beneath the starboard beam, and the space between said firstand second truck units is unobstructed. First and second extensibleframe supporting members each connect a corresponding truck unit withand support its respective superjacent longitudinal beam. At least oneof such frame supporting members includes an upwardly extensiblehydraulic ram or operator arranged to elevate the longitudinal beamrelative to the truck unit. A fluid dispensing means provides controlledvolumes of fluid under pressure to the hydraulic ram or rams, saiddispensing means in combination with the hydraulic ram means beingoperative to raise or lower said U-frame in a substantially horizontalplane. The U'frame is further characterized in that said longitudinalbeams, either alone or together with said forward transverse beam,constitute the sole members of the boat carrier which contact andsupport the hull of the boat to be transported.

The term "Ll-frame, as employed herein and in the appended claims, isintended to denote not only a frame having a rectangular or box-likeforward end, but it includes other geometric configurations as well.That is to say, the forward transverse beam member can be semi-circular,semi-elliptical or of other arcuate shape, or it may be V-shaped toconform approximately with the bow portion of the hull of the boat to betransported. It is, however, an important and distinguishing facet ofour invention that the after end of the U-frame is open and the areabounded by the U-frame is unobstructed from its after end throughoutsubstantially its entire length. Stated otherwise, the rectangularparallelpipedal volume bounded by the U-frame in the upper plane, and bythe vertical projection of the Uframe on the ground in the lower plane,is substantially unobstructed, save for the optional slight protrusioninto such volume of certain of the vehicle wheels. This is a primerequisite of the invention so that, when it is backed into positionbeneath a boat, it will freely clear the fixed boat support means and beimmediately operational to lift the boat, all without having todisassemble and reassemble any load-bearing crossbars and without havingto disturb the fixed boat support means. It is also an importantcharacteristic of the invention that the longitudinal beam members ofthe U-frame, either alone or together with the forward transverse beammember, constitute the sole members of the boat carrier which contactand support the hull of the boat to be transported. Such an arrangement,precluding the use of beamloaded crossbars, ensures that the hull willbe supported by the longitudinal beam elements along laterally spacedapart lines of contact which are parallel with the keel and at aslightly higher elevation than the keel, thereby assuring that the boatwhen raised will comprise a relatively stable load which issubstantially restrained from a rolling motion relative to the U- frame.

A further significant feature of our invention is that the U- frame iscarried by a pair of laterally spaced apart, independent truck unitswhich are preferably positioned beneath the after end portions of theU-frame. This construction eliminates the need for a separate vehiclechassis member which in turn permits the vehicle to be of minimum width.Although each after truck unit may have as few as one or two wheels, itis preferred that each truck per se comprise a stable mobile platform,i.e., one having at least a three-point contact with the ground.Therefore, each after truck unit preferably comprises at least threewheels, at least two of which wheels are laterally spaced apart upon afirst common axis of rotation. At least one other wheel has a secondaxis of rotation which is longitudinally spaced from the first axis ofrotation, and both the first and second axes of rotation areperpendicular to the longitudinal beam members. In a distinctlypreferred embodiment of our invention, each after truck has two pairs ofwheels arranged in tandem in a manner similar to aircraft landing gear.A more specific refinement of the after truck units involves theirinterconnection with the extensible frame supporting members in such amanner as to permit each truck to undergo at least a limited freeoscillation or rocking movement in the vertical plane relative to theU-frame about a horizontal axis (sometimes referred to as pitch) wherebyto minimize the amplitude of vertical displacements which may beimparted to the U-frame when the boat carrier is traversing bumpyground. Another specific refinement of the after truck units involvestheir interconnection with the extensible frame supporting members insuch a manner as to substantially preclude oscillatory rotation orswivel motion of the truck unit about a vertical axis (sometimesreferred to as "yaw) whereby proper alignment of the longitudinal beamsrelative to the boat can be readily maintained, and control of degree ofturn is singularly determined by a third or forward dolly truck unit.

In a preferred embodiment of the invention, there is provided a forwarddolly truck, comprising at least one and preferably at least twolaterally spaced apart wheels, such dolly truck unit being positionedbeneath the forward transverse beam member at a locus preferably midwaybetween the longitudinal beam members. The dolly truck is connected withthe transverse beam member by a vertical telescoping com pressionmember, such compression member desirably being constructed and arrangedto permit substantial rotation of the dolly truck relative to theforward line of travel, and will preferably be such as to permit atleast about a 190 rotation of the dolly truck unit relative to forwardline of travel. Thus, the turning radius of the boat carrier is notmaterially greater than its own axIe-to-axle length.

As previously indicated, at least one of the extensible frame supportingmembers which connect the after truck units with their respectivesuperjacent longitudinal beam members will also comprise an upwardlyextensible hydraulic ram or linear hydraulic operator. Preferably, bothof the afier extensible frame supporting members will include ahydraulic ram means operatively associated therewith. Still morepreferably, the aforesaid telescoping compression member which supportsthe transverse beam member upon the forward dolly truck unit will alsoinclude an upwardly extensible hydraulic ram means. Therefore, in adistinctly preferred embodiment of the invention, the entire U-frame canbe subjected to lifting vectors applied at the vertices of an isoscelestriangle, two at the after ends of the U and the third at the forward orclosed end of the U. The term hydraulic, as employed herein and in theappended claims, comprehends the use both of incompressible hydraulicfluid, e.g., oil, and also gas under superatmospheric pressure such ascompressed air, compresed nitrogen and gaseous carbon dioxide which maybe supplied from a reservoir of liquid or solid C0,. It is preferred,however, that the hydraulic system be filled with a normally liquidhydraulic medium, such as oil, which can be supplied in controlledvolumes to the hydraulic ram members by one or more manually operated ormotor driven hydraulic pumps.

DESCRIPTION OF THE DRAWINGS The structure and mode of operation of ourinvention may be more fully described and better understood by referenceto the accompanying drawings in which:

FIG. 1 is a plan view ofthe boat carrier.

FIG. 2 is a side elevation view of the boat carrier in a retracted orunloaded position.

FIG. 3 is a side elevation view of the boat carrier in an elevated, loadsupporting position.

FIG. 4 is a front elevation view of the boat carrier.

FIG. 5 is an enlarged side elevation view of the forward dolly assemblytaken along 55 of FIG. 1.

FIG. 6 is an enlarged rear elevation view of the forward dolly assembly.

FIG. 7 is an enlarged side elevation view of an after truck unit.

FIG. 8 is an isometric view of the after portion of the U- frame membershowing the use of a disconnectable framereinforcing crossbar.

DETAILED DESCRIPTION OF THE INVENTION With reference now to FIG. 1, theboat carrier comprises a horizontal U-frame, denoted generally bynumeral 10, which in turn is made up ofa port longitudinal beam memberII, a starboard longitudinal beam member 12 and a forward transversebeam member 13. By way of illustration, these three elements can beformed of 3-inch ID steel pipe, all connections being welded unlessotherwise indicated. As explained more fully hereinbelow, the U-framemay be subject to "spreading," under certain conditions, and thereforeto reinforce and rigidify the U-frame there are provided short diagonalstruts or braces 14 and 14 across the angles. These strengthening bracesremain out of contact with the boat hull and are subject to tensileloading only; in lieu thereof, one may employ gusset plates or otherequivalent structure. Disposed along the top of the after end portionsof beams I] and 12 are hull pads or cushions 15, 15'. These pads may beformed of cotton batting, sponge rubber, open cell foamed plastic or anyother soft resilient material. A keel rest 16 is secured to the middleof the forward transverse beam 13.

An after port truck unit, denoted generally by numeral 20, is positionedbeneath the after end of beam II. This truck is fitted with fourpneumatic rubber tired wheels arranged in tandem: a front inboard wheel52, a front outboard wheel 53, a rear inboard wheel 55 and a rearoutboard wheel 56. The construction of this truck, as well as itsassociated frame support and elevating means, will be more particularlydescribed hereinbelow. An after starboard truck unit, denoted generallyby numeral 21, is positioned beneath the after end of beam 12. Truck 21is identical to port truck 20 and is similarly fitted with fourpneumatic tired wheels arranged in tandem: a front inboard wheel 52 afront outboard wheel 53' ,a rear inboard wheel 55' and a rear outboardwheel 56'. A forward dolly truck unit, denoted generally by numeral 22,is positioned beneath the midpoint of forward transverse beam 13. Dolly22 is provided with two pneumatic rubber tired wheels: port wheel 34 andstarboard wheel 34'. The construction of dolly 22, as well as itsassociated frame support and elevating means, will be more particularlydescribed hereinbelow. Three hydraulic hand pumps 23, 24, and 25 aremounted upon the forward transverse beam 13. These pumps delivercontrolled volumes of high pressure hydraulic fluid through small borecopper tubing to three corresponding hydraulic rams operativelyassociated with the after port and starboard trucks and the forwarddolly truck. Pump 23 operates a ram at the forward axle, pump 24operates a ram at the starboard after truck and pump 25 operates a ramat the port after truck. Each of these pumps is equipped with check andrelease valves and is of conventional design. Thus, any of the threeextensible frame supports can be raised or lowered at will from theoperators position at the front end of the boat carrier.

The detailed construction and assembly of the forward dolly truck 22 isbest seen in FIGS. 4, 5, and 6. A bed plate or channel 30 is providedwith opposing axle mounting plates 31, 31 and opposing tongue mountingplates 32, 32'. Stub axles 33, 33 are welded to plates 31, 31respectively. Wheel 34 is journaled to axle 33, and wheel 34 isjournaled to axle 33. The journal fittings of these wheels may andpreferably do comprise ball bearings to reduce friction. The U-framesupport and elevating means is a vertically extending telescopingcompression member comprising a lower inner guide sleeve 35, an upperouter guide sleeve 36 concentric about sleeve 35, and a hydraulic ram 37mounted within sleeves 35 and 36. Sleeve 35 is welded to bed plate 30and projects upwardly therefrom. Sleeve 36 depends from and is welded tosuperjacent transverse beam I3. Sleeves 35 and 36 are coaxially alignedand are in slidable, slip-fitting engagement with each other, wherebythe dolly 22 is freely rotatable about a vertical axis relative to theUframe l0 and, at the same time, the U-frame is freely elevatable over apredetermined span relative to the dolly 22. Hydraulic oil is deliveredfrom hand pump 23 to ram 37 via tubing 38. An elongated vertical slot 39is cut in the rear wall of the outer sleeve 36 to furnish access forinstallation of the hydraulic operator and to provide clearance for theconnecting pressure tubing. The dolly assembly is completed by a tongueor tow bar 40, which is pivotally connected to mounting plates 32, 32'by a bolt 41. The forward end of the tongue can be fitted with aconventional female ball joint coupling (not illustrated) for attachmentto a tow truck, tractor or other selfpropelled vehicle.

The detailed construction and assembly of the after truck units andtheir respective extensible frame supporting members is best seen inFIGS. 4, 7, and 8. FIG. 7 is a side elevation view of after port truckwith the outboard wheels cut away. It will be understood that starboardtruck 21 is identical to truck 20, and corresponding elements of thestarboard truck bear the same numerals except primed. As shown in FIGS.4 and 7, the port truck is built around a bedplate or channel section 50which carries a front axle 51 and a rear axle 54. Wheels 52 and 53 arejournaled to axle 51, and wheels 55 and 56 are journaled to axle 54. Thejournal fittings of all wheels may and preferably do comprise ballbearings to reduce friction. The extensible frame supporting member is afully pivoted Y-frame defined by a rigid strut 57 and a hydraulic ram66, the latter, of course, being extendable and retractable. Strut 57is, in turn, composed of parallel laterally spaced side bars 58 and 59which are joined together by an intermediate batten plate 60. The upperend of strut 57 brackets the superjacent longitudinal beam 11 and ispivotally connected thereto by a pin or bolt 61. The lower end of strut57 brackets the bedplate 50 and is pivotally connected thereto by a pinor bolt 62. An elongated slot 63 formed in the bottom of the after endportion of beam I1 furnishes operating clearance for ram 66. The afterend of beam 11 is an gularly cut, as illustrated, across which openingis welded an endcap 64. A pivot bracket 65 is attached to the inner faceof endcap 64. Hydraulic ram 66 is pivotally connected at its upper endby a pin 68 which in turn connects with bracket 65. The lower end oroperating rod of ram 66 is pivotally connected to strut 57 by pin 67 ata locus intermediate the pivot points 61, 62. Hydraulic fluid issupplied to operator 66 by small bore copper tubing 69. Tubing 69 isconveniently run lengthwise through the hollow interior of beam 1] toconnect with hand pump 25 at the forward end of the boat carrier. As ram66 is extended upwardly and rearwardly from its most retracted position,strut 57 will rotate in the clockwise direction about pivot point 62,and longitudinal beam member It will swing upwardly and rearwardlyrelative to truck 20.

It will be observed that, since truck 20 is connected to strut 57 at asingle pivot point 62 intermediate axles 51 and 54, the truck is free toundergo at least a limited oscillation or pitching motion in thevertical plane about axis 62. Therefore, when the boat carrier is movingover a rough road, the front and rear wheels of the truck unit cantolerate relatively large vertical displacements whereas the amplitudeof the corresponding vertical displacement transmitted to strut 57, andconsequently to beam 11, will be relatively small. The starboard truckwill, of course, behave the same way; however, since the port andstarboard trucks are independent of each other, their pitching motionsneed not be synchronous. Such attenuation of road shock byteeter-totter" effect is very advantageous because it eliminates theneed for a spring suspension system.

It will also be observed that composite strut 57 has substantial widthand rigidity and that it brackets or straddles both the beam 11 andbedplate S0 at pivot points 6] and 62 respective ly. The resultingrestraint against torsional displacement substantially precludes anyswivel or yawing motion of truck 20 about a vertical axis relative tobeam 11. Proper alignment of the longitudinal beams and parallelism ofthe after truck units are thereby readily maintained regardless ofwhether the boat carrier is being towed or pushed.

The problem ofspreading has previously been alluded to. The geometry ofa typical boat hull takes the form of a V- shaped or downwardly convexarcuate or gull-wing cross-section, any of which cause the hull to actas a wedge-shaped load upon the Uframe. With a pure U configuration, thelongitudinal members 1! and 12 can be treated as cantilever beams. Themagnitude of the horizontal load component acting on these beamsincreases with weight of the boat and/or hull angle and may beappreciable. Therefore, to reduce the maximum lateral deflection of thelongitudinal beams as well as to preclude excessive bending stressesfrom developing therein, we have found it advisable, under certainconditions, to employ a disconnectable tension member or tie barconnecting the after ends of the longitudinal beams. These conditionsare: when the weight of the boat approaches the maximum rated capacityof the carrier, the relatively long hauls, or when the route to betraveled is rough.

The use of such tie bar is illustrated in FIG. 8. The endcaps 64, 64'are provided with L-shaped lugs and 80 respectively. The tie bar itselfcomprises a straight transverse section 81 terminating in short upwardlyprojecting legs 82, 83. These legs are provided with slots which alignwith and engage lugs 80, 80'. The purpose of this design is to preventthe tie bar from coming into load-bearing contact with the bottom of thehull of the boat, inasmuch as the transom of a boat of customary sizewill substantially overhang the after end of the U- frame. The tie baris removed before the carrier is backed into position beneath the boat.When this is accomplished, the tie bar is then hand connected across theafter ends of the U- frame before the U-frame is elevated to lift theboat. It will be appreciated that the tie bar is subject to tensileloading only and is free of beam loading. Its effect is to convert asimple cantilever beam to a restrained cantilever beam, therebysubstantially rigidifying the U-frame member.

The mode of operation of our invention is explained with reference toFIGS. 1, 2, 3, and 4. In FIG. 1, the boat carrier is shown backed intoposition beneath a boat indicated by dashed line 28. The fixed oronground support of boat 28 is, in this example, comprised of a forwardsawbuck 26 and an after sawbuck 27. The carrier straddles the forwardsawbuck. It need not straddle the after sawbuck but can be pushed rightup to it since the after sawbuck supports the boat just forward of thetransom. When the carrier is being pushed into position under the boat,it is, of course, in the down or retracted position as shown in FIG. 2.The workman will then operate in sequence selected ones of handpumps 23,24, and 25, or any two simultaneously as desired, so that the U-frame 10will be elevated in a substantially horizontal plane. In FIG. 3, thecarrier is shown in a more fully extended elevated position. The degreeof elevation need only be sufficient to lift the boat clear of itson-ground support. Since the after truck units 20 and 21 are pivotallyconnected to U-frame 10 by the above described Y-frame assembly, whereasthe dolly truck 22 is restrained from longitudinal motion relative tothe U-frame, the after truck units will move forward a short distance asthe boat is engaged and raised. At this point, the assembly is in atowing or movable position. In FIG. 4, the boat 28 is shown resting uponpads and 15 and also upon keel rest 16. The regions of contact are overelongated areas on either side of the keel and parallel therewith andalso under the keel just aft of the how. This provides a very stablesupport platform, and no hull bracing or other auxiliary supports arerequired. It will also be noted that the after trucks and 21 aredisposed completely beneath the hull. By virtue of the compactconstruction of the boat carrier and the freewheeling action of theforward dolly, the entire carrier with boat on it is so maneuverablethat it can be moved into or out of a space exactly the width of theboat or exactly the width of the carrier. If the ground is level enough,the boat carrier can be towed by hand. In the case of rough or hillyterrain, it is preferable to employ a tow truck or small tractor.

Although we do not intend the scope of our invention to be limited as tosize, an example of suitable dimensions is given below:

U-frame construction 3" 10 steel pipe Length of U-frame [0 feet Width ofcarrier (lateral spacing between inboard wheels of after trucks) 40inches The weight capacity of this boat carrier is approximately 4,500lbs. The boat length capacity is about 24 feet with the usual beam of aboat of that length. Of course, it can accommodate smaller boats also.It is of optimum size to handle outboards and runabouts whichpredominate in any boat yard.

Those skilled in the art will be cognizant that many variations of theapparatus specifically described herein are included within the broadscope of our invention. For example, in lieu of tubular members, theU-frame may be constructed of l-beams, WF-beams or trussed beams.Instead of a plurality of hydraulic pumps, one may utilize a single pumphaving a common discharge to several hydraulic rams. In the latterevent, it may be desirable to incorporate appropriate flow meteringmeans so that equal aliquots of oil are dispensed to the cylindersduring each pump stroke. The hydraulic pump or pumps may be motor drivenif desired. And as indicated supra one may use, instead of oil, acompressible fluid such as compressed air, high pressure nitrogen orcarbon dioxide. With respect to the after truck and dolly units, thenumber of wheels per unit may be greater or lesser than thosespecifically illustrated.

By way of summary, the advantages of our invention are many. The boatcarrier is light and durable and does not require any special skills tooperate. Most importantly, it immediately eliminates the need for two orthree extra men to move boats from one place to another in a boat yard,show room or on used and new boat display lots. The ease with which thiscan be done makes the boat carrier attractive for any boat yard operatoror boat dealer because he can quickly pull a boat out from a line-up"either for moving to another place or for showing purposes.

We claim as our invention:

1. A boat carrier comprising l. a substantially horizontal U-framemember defined by a pair of laterally spaced apart substantiallyparallel port and starboard longitudinal beam members and a transversebeam member connecting the forward ends of said longitudinal beammembers, the after end of the U-frame being open and the area bounded bythe U-frame being unobstructed from its after end throughoutsubstantially its entire length;

2. a first multiple wheeled truck unit positioned beneath said port beammember;

3. a second multiple wheeled truck unit positioned beneath saidstarboard beam member, the space between said first and second truckunits being unobstructed;

4. each of said first and second truck units comprising a bed platehaving an after end and a forward end, a first pair of laterally spacedapart wheels having a first common axis of rotation journaled to one endof the bed plate, at least one other wheel having a second axis ofrotation journaled to the other end of the bed plate;

5. first and second extensible frame supporting members each connectinga corresponding one of said first and second truck units with andsupporting its respective superjacent longitudinal beam member, each ofsaid frame supporting members including an upwardly extensible hydraulicram means arranged to elevate the longitudinal beam member relative tothe truck unit, each of said frame supporting members comprising a strutmember pivotally connected at its upper end to the longitudinal beammember and pivotally connected at its lower end to the bed plate of itsassociated truck unit at a locus intermediate said first and second axesof rotation, said hydraulic ram means being pivotally connected to saidstrut member at a locus intermediate the ends thereof and also pivotallyconnected at its opposite end to said longitudinal beam member at alocus which is longitudinally spaced from the point of pivotalattachment of said strut member to said longitudinal beam member, theupper end of said strut member bracketing its respective superjacentlongitudinal beam member and the lower end of said strut memberbracketing said bed plate whereby to maintain said first and second axesof rotation perpendicular to said longitudinal beam member and tosubstantially preclude rotation of its respective truck unit about avertical axis;

. fluid dispensing means providing controlled volumes of fluid underpressure in fluid communication with said hydraulic ram means, saiddispensing means in combination with said hydraulic ram means beingoperative to raise or lower said U-frame member in a substantiallyhorizontal plane; and

7. said U-frame member being further characterized in that saidlongitudinal beam members, either alone or together with said forwardtransverse beam member, constitute the sole members of the boat carrierwhich contact and support the hull of the boat to be transported.

2. The boat carrier of claim 1 further characterized in that said firstand second truck units are positioned beneath the after end portions ofsaid longitudinal beam members.

3. The boat carrier of claim 1 further characterized in that a dollytruck unit is positioned beneath said forward transverse beam member ata locus approximately midway between said longitudinal beam members, anda vertical telescoping compression member, including upwardly extensiblehydraulic ram means, connects said dolly truck unit with and supportssaid transverse beam member.

4. The boat carrier of claim 3 wherein said dolly truck unit has a pairof wheels on a common axis of rotation.

5. The boat carrier of claim 4 further characterized in that saidtelescoping compression member is constructed and arranged to permitsubstantial rotation of the dolly truck unit relative to forward line oftravel.

6. The boat carrier of claim 3 further characterized in the provision ofa disconnectable tie bar connecting the after end portions of said portand starboard longitudinal beam members, said tie bar serving torigidify said U-frame member when the latter is under load, and said tiebar being constructed and arranged to be free of load bearing contactwith the hull of the boat to be transported.

7. A boat carrier comprising LII a substantially horizontal U-framemember defined by a pair of laterally spaced apart substantiallyparallel port and starboard longitudinal beam members and a transversebeam member connecting the forward ends of said longitudinal beammembers, the after end of the U-frarne being open and the area boundedby the U-frame being unobstructed from its after end throughoutsubstantially its entire length;

. a first multiple wheeled truck unit positioned beneath the after endof said port beam member;

a second multiple wheeled truck unit positioned beneath the after end ofsaid starboard beam member, the space between said first and secondtruck units being unob structed;

. each of said first and second truck units comprising a bed platehaving an after end and a forward end, a first pair of laterally spacedapart wheels having a first common axis of rotation journaled to saidforward end of the bed plate, a second pair of laterally spaced apartwheels having a second common axis of rotation journaled to said afterend ofthe bed plate;

. first and second extensible frame supporting members lower end to thebed plate of its associated truck unit at a locus intermediate saidfirst and second axes of rotation, said hydraulic ram means beingpivotally connected to said strut member at a locus intermediate theends thereof and also pivotally connected at its opposite end to saidlongitudinal beam member at a locus which is longitudinally spaced fromthe point of pivotal attachment of said strut member to saidlongitudinal beam member, the upper end of said strut member bracketingits respective superjacent longitudinal beam member and the lower end ofsaid strut member bracketing said bed plate whereby to maintain saidfirst and second axes of rotation perpendicular to said longitudinalbeam member and to substantially preclude rotation of its respectivetruck unit about a vertical axis;

. a dolly truck unit positioned beneath said forward transfluiddispensing means providing controlled volumes of fluid under pressure influid communication with said hydraulic ram means, said dispensing meansin combina tion with said hydraulic ram means being operative to raiseor lower said U-frame member in a substantially horizontal plane; and

. said U-frame member being further characterized in that saidlongitudinal beam members, either alone or together with said forwardtransverse beam member, constitute the sole members of the boat carrierwhich contact and support the hull of the boat to be transported.

1. A boat carrier comprising
 1. a substantially horizontal U-framemember defined by a pair of laterally spaced apart substantiallyparallel port and starboard longitudinal beam members and a transversebeam member connecting the forward ends of said longitudinal beammembers, the after end of the U-frame being open and the area bounded bythe U-frame being unobstructed from its after end throughoutsubstantially its entire length;
 2. a first multiple wheeled truck unitpositioned beneath said port beam member;
 3. a second multiple wheeledtruck unit positioned beneath said starboard beam member, the spacebetween said first and second truck units being unobstructed;
 4. each ofsaid first and second truck units comprising a bed plate having an afterend and a forward end, a first pair of laterally spaced apart wheelshaving a first common axis of rotation journaled to one end of the bedplate, at least one other wheel having a second axis of rotationjournaled to the other end of the bed plate;
 5. first and secondextensible frame supporting members each connecting a corresponding oneof said first and second truck units with and supporting its respectivesuperjacent longitudinal beam member, each of said frame supportingmembers including an upwardly extensible hydraulic ram means arranged toelevate the longitudinal beam member relative to the truck unit, each ofsaid frame supporting members comprising a strut member pivotallyconnected at its upper end to the longitudinal beam member and pivotallyconnected at its lower end to the bed plate of its associated truck unitat a locus intermediate said first and second axes of rotation, saidhydraulic ram means being pivotally connected to said strut member at alocus intermediate the ends thereof and also pivotally connected at itsopposite end to said longitudinal beam member at a locus which islongitudinally spaced from the point of pivotal attachment of said strutmember to said longitudinal beam member, the upper end of said strutmember bracketing its respective superjacent longitudinal beam memberand the lower end of said strut member bracketing said bed plate wherebyto maintain said first and second axes of rotation perpendicular to saidlongitudinal beam member and to substantially preclude rotation of itsrespective truck unit about a vertical axis;
 6. fluid dispensing meansproviding controlled volumes of fluid under pressure in fluidcommunication with said hydraulic ram means, said dispensing means incombination with said hydraulic ram means being operative to raise orlower said U-frame member in a substantially horizontal plane; and 7.said U-frame member being further characterized in that saidlongitudinal beam members, either alone or together with said forwardtransverse beam member, constitute the sole members of the boat carrierwhich contact and support the hull of the boat to be transported.
 2. Theboat carrier of claim 1 further characterized in that said first andsecond truck units are positioned beneath the after end portions of saidlongitudinal beam members.
 2. a first multiple wheeled truck unitpositioned beneath said port beam member;
 2. a first multiple wheeledtruck unit positioned beneath the after end of said port beam member; 3.a second multiple wheeled truCk unit positioned beneath the after end ofsaid starboard beam member, the space between said first and secondtruck units being unobstructed;
 3. The boat carrier of claim 1 furthercharacterized in that a dolly truck unit is positioned beneath saidforward transverse beam member at a locus approximately midway betweensaid longitudinal beam members, and a vertical telescoping compressionmember, including upwardly extensible hydraulic ram means, connects saiddolly truck unit with and supports said transverse beam member.
 3. asecond multiple wheeled truck unit positioned beneath said starboardbeam member, the space between said first and second truck units beingunobstructed;
 4. each of said first and second truck units comprising abed plate having an after end and a forward end, a first pair oflaterally spaced apart wheels having a first common axis of rotationjournaled to one end of the bed plate, at least one other wheel having asecond axis of rotation journaled to the other end of the bed plate; 4.The boat carrier of claim 3 wherein said dolly truck unit has a pair ofwheels on a common axis of rotation.
 4. each of said first and secondtruck units comprising a bed plate having an after end and a forwardend, a first pair of laterally spaced apart wheels having a first commonaxis of rotation journaled to said forward end of the bed plate, asecond pair of laterally spaced apart wheels having a second common axisof rotation journaled to said after end of the bed plate;
 5. first andsecond extensible frame supporting members each connecting acorresponding one of said first and second truck units with andsupporting its respective superjacent longitudinal beam member, each ofsaid frame supporting members including an upwardly extensible hydraulicram means arranged to elevate the longitudinal beam member relative tothe truck unit, each of said frame supporting members comprising a strutmember pivotally connected at its upper end to its respectivelongitudinal beam member and pivotally connected at its lower end to thebed plate of its associated truck unit at a locus intermediate saidfirst and second axes of rotation, said hydraulic ram means beingpivotally connected to said strut member at a locus intermediate theends thereof and also pivotally connected at its opposite end to saidlongitudinal beam member at a locus which is longitudinally spaced fromthe point of pivotal attachment of said strut member to saidlongitudinal beam member, the upper end of said strut member bracketingits respective superjacent longitudinal beam member and the lower end ofsaid strut member bracketing said bed plate whereby to maintain saidfirst and second axes of rotation perpendicular to said longitudinalbeam member and to substantially preclude rotation of its respectivetruck unit about a vertical axis;
 5. The boat carrier of claim 4 furthercharacterized in that said telescoping compression member is constructedand arranged to permit substantial rotation of the dolly truck unitrelative to forward line of travel.
 5. first and second extensible framesupporting members each connecting a corresponding one of said first andsecond truck units with and supporting its respective superjacentlongitudinal beam member, each of said frame supporting membersincluding an upwardly extensible hydraulic ram means arranged to elevatethe longitudinal beam member relative to the truck unit, each of saidframe supporting members comprising a strut member pivotally connectedat its upper end to the longitudinal beam member and pivotally connectedat its lower end to the bed plate of its associated truck unit at alocus intermediate said first and second axes of rotation, saidhydraulic ram means being pivotally connected to said strut member at alocus intermediate the ends thereof and also pivotally connected at itsopposite end to said longitudinal beam member at a locus which islongitudinally spaced from the point of pivotal attachment of said strutmember to said longitudinal beam member, the upper end of said strutmember bracketing its respective superjacent longitudinal beam memberand the lower end of said strut member bracketing said bed plate wherebyto maintain said first and second axes of rotation perpendicular to saidlongitudinal beam member and to substantially preclude rotation of itsrespective truck unit about a vertical axis;
 6. fluid dispensing meansproviding controlled volumes of fluid under pressure in fluidcommunication with said hydraulic ram means, said dispensing means incombination with said hydraulic ram means being operative to raise orlower said U-frame member in a substantially horizontal plane; and 6.The boat carrier of claim 3 further characterized in the provision of adisconnectable tie bar connecting the after end portions of said portand starboard longitudinal beam members, said tie bar serving torigidify said U-frame member when the latter is under load, and said tiebar being constructed and arranged to be free of load bearing contactwith the hull of the boat to be transported.
 6. a dolly truck unitpositioned beneath said forward transverse beam member, and atelescoping compression member, including upwardly extensible hydraulicram means arranged to elevate the transverse beam member relative tosaid dolly truck unit, connecting said dolly unit with and supportingsaid transverse beam member, said compression member being constructedand arranged to permit at least about + or - 90* rotation of said dollytruck unit relative to forward line of travel;
 7. fluid dispensing meansproviding controlled volumes of fluid under pressure in fluidcommunication with said hydraulic ram means, said dispensing means incombination with said hydraulic ram means being operative to raise orlower said U-frame member in a substantially horizontal plane; and
 7. Aboat carrier comprising
 7. said U-frame member being furthercharacterized in that said longitudinal beam members, either alone ortogether with said forward transverse beam member, constitute the solemembers of the boat carrier which contact and support the hull of theboat to be transported.
 8. said U-frame member being furthercharacterized in that said longitudinal beam members, either alone ortogether with said forward transverse beam member, constitute the solemembers of the boat carrier which contact and support the hull of theboat to be transported.